1. Technical Field
The present disclosure relates to zoom lenses. More particularly, the present disclosure relates to superzoom lenses.
2. Description of Related Art
One kind of zoom lenses, disclosed in U.S. Pat. No. 7,420,745, includes a first lens group, a second lens group, an aperture, a third lens group, and a fourth lens group arranged from an object side to an image side on an optical axis for a digital camera, a digital video camera, or a personal digital assistant (PDA).
The first lens group has positive optical power. The second lens group has negative optical power. The third lens group has positive optical power. The fourth lens group with positive optical power. The first lens group moves toward the object side when the zoom lenses are extended.
Furthermore, the second lens group includes a negative lens, a positive lens, and a negative lens arranged from the object side to the image side on an optical axis. The positive lens and the negative lens located close to the image side are cemented together.
As mentioned above, the second lens group has at least three lenses. Therefore, the thickness of the zoom lenses is increased when the zoom lenses is collapsed.